Electrical power converter method and system employing multiple-output converters

ABSTRACT

A support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support, in conjunction with other packaging features may form a shield from both external EMI/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 10/252,296filed Dec. 18, 2002.

This application claims the benefit of U.S. Provisional Application No.60/349,259, filed Jan. 16, 2002.

GOVERNMENT LICENSE RIGHTS

This invention was made with Government support under CooperativeAgreement No. DE-FC02-99EE50571 awarded by the Department of Energy. TheGovernment has certain rights in this invention.

BACKGROUND OF THE INVENTION

The present technique relates to power electronic devices and theirincorporation into modules and systems. More particularly, the techniquerelates to the configuration, packaging and thermal management of powerelectronic devices, particularly in modular power converters.

A wide array of applications are known for power electronic devices,such as power switches, transistors, and the like. For example, inindustrial applications, silicon controlled rectifiers (SCRs), insulatedgate bipolar transistors (IGBTs), field effect transistors (FETs), andso forth are used to provide power to loads. In certain applications,for example, arrays of power switches are employed to convert directcurrent power to alternating current waveforms for application to loads.Such applications include motor drives. However, many more applicationsexist for inverter circuitry and other circuitry incorporating suchdevices. Other settings include electric vehicle applications grid tieinverters, DC to DC converters, AC to AC power Converters, and manyother solid state power conversion elements that require a packagedpower device switch topology. In electric vehicles, a source of directcurrent is typically available from a battery or power supply systemincorporating a battery or other direct or rotating energy converter.Power electronic devices are employed to convert this power toalternating current waveforms for driving one or more electric motors.The motors serve to drive power transmission elements to propel thevehicle. While numerous constraints exist in such settings which differfrom those of industrial settings, numerous problems and difficultiesare shared in all such applications.

Demands made on power electronic devices typically include theirreliability, power output, size and weight limits, and requirementsregarding the environmental conditions under which they must operate.Where size and weight constraints force reductions in the packagingdimensions, difficulties arise in appropriately placing the powerelectronic devices, and drive and control circuitry associated with thedevices to sufficiently remove heat generated during their operation.Where size, cost and weight are less important, large heat sinks andheat dissipation devices may be employed utilizing any fluid that can beaccommodated by choice of materials that are compatible. However, aspackaging sizes are reduced, more efficient and effective techniques areneeded. Electrical and electronic constraints also impose difficultieson package design. For example, reduction of inductance in the circuitsand circuit layout is commonly a goal, while solutions for reducinginductance may be difficult to realize. Shielding from electromagneticinterference originating both within the package and outside the packagemay be important, depending upon the surrounding environment. Similarly,appropriate interfacing with external circuitry, and the facility toinstall, service and replace power electronics packages may be importantin certain applications. It has typically been necessary in manyinstances to configure the power electronic element to match closely thespecific needs of the application and by doing so meet cost, size,performance targets that can be achieved by no other means. Finally,certain environments, such as vehicle environments, impose a wide rangeof difficult operating conditions, including large temperature spans,vibration and shock loading, and so forth.

There is a need, therefore, for improved techniques in packaging ofpower electronic devices. There is a particular need for techniqueswhich offer highly efficient and cost-effective power capabilities insmall, robust, and thermally managed configurations.

SUMMARY OF THE INVENTION

The present technique provides power electronics modules designed torespond to such needs. The technique makes use of novel packaging,thermal management, interconnect, and grounding shielding approacheswhich both improve performance, and offer smaller, lighter and moreefficient configurations of the power electronic devices and their drivecircuitry. The technique offers multiple facets for such packaging andthermal management which can be adapted to a variety of settings,including industrial power electronics applications, vehicularapplications, and so forth. Many of the embodiments of the presenttechnique permit utilization of standardized cells designed to bereconfigured into a number of optimum configurations matching keyapplication requirements.

The features of the technique offer modular packaging, such as around athermal management system, generally including a thermal support. Powerelectronic devices may be mounted directly to the support for removal ofheat. The arrangement of the devices, and their interconnection withincoming and outgoing power conductors may vary, and may make use of thethermal support for extraction of heat and for mounting of variouscomponents. A number of improved power device assemblies, theirattachment means to the thermal support are accommodated with the scopeof the present technique.

In an exemplary embodiment, a modular power converter is featured,although other types of power electronic circuitry, including variouspower converting circuitry and drives, and so forth, may be adapted inthe package. Incoming power conductors interface with the powerelectronics circuitry, which converts the incoming power to desiredoutput power, such as alternating current waveforms. The incoming andoutgoing power conductor configurations and arrangements may facilitateinstallation of the module into enclosures or vehicular mounting spaces,with plug-in connections being offered for both power and control.Coolant may be routed through the thermal base via additionalconnections. Exemplary coolant configurations are envisaged thateffectively extract heat by close and thermally matched mounting ofpower electronics and other electronic devices immediately adjacent toheat removal surfaces. Locations, positioning and interconnection ofcontrol, drive, and power electronic circuitry facilitate closepackaging of these elements.

Shielding from electromagnetic interference may be facilitated throughthe use of a shielding support, which may be a thermal support and,where desired, additional external shielding and closures. Optimum powerdevice temperature and EMI regulation means may be accommodated in theintrinsic features of the support, such that they work in close harmonywith electrical power switching elements or other circuitry and theirthermomechanical attachment to both the inputs, outputs and the support,EMI-management and thermal-management system.

The present technique offers a wide range of improvements in powerelectronics packaging and management. The improvements reside both inthe particular configuration of the packages, the configuration of thepackage components and the interrelationship and layout of thecomponents, their interfaces, and their operational interdependence. Thetechnique also offers more effective shielding from EMI/RFI. Moreover,better high frequency grounds may be achieved by low inductanceconnection means integrated into the support. Connections may be cooledby means of integrated bus structure in contact with electricallyinsulating but thermally conductive features in or integrated with thesupport and coolant circulating system.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other advantages and features of the invention willbecome apparent upon reading the following detailed description and uponreference to the drawings in which:

FIG. 1 is a diagrammatical representation of a power electronics modulein accordance with certain aspects of the present technique;

FIG. 2 is a diagrammatical representation of a variation of the moduleof FIG. 1 including additional circuitry supported on a thermal base;

FIG. 3 is a further diagrammatical representation of a power electronicsmodule having power electronic devices mounted to two sides of a thermalbase;

FIG. 4 is a diagrammatical representation of a power electronics modulehaving multiple thermal bases;

FIG. 5 is a block diagram of certain functional circuitry in anexemplary application of a power electronics module in accordance withaspects of the present technique for a vehicle drive;

FIG. 6 is a diagram of a power electronics module in accordance withaspects of the present technique employed in an enclosure, such as in avehicle or industrial setting;

FIGS. 7A and 7B are block diagrams of functional circuitry which may besupported in a package in accordance with the present techniques,including an inverter drive and a converter drive;

FIG. 8 is an exploded perspective view of an exemplary power electronicsmodule and its associated packaging components;

FIG. 9 is a perspective view of the external interfaces of an exemplarypackage module of the type illustrated in FIG. 8, with slightlydifferent interface connections;

FIG. 10 is a perspective view of the package module of FIG. 9illustrating additional interfaces on a rear side of the module package;

FIG. 11 is a perspective view of the package of FIG. 10 with a housingcover removed to display internal arrangements of power electronics andassociated circuitry and components;

FIG. 12 is a perspective view of the internal power module as shown inFIG. 11 with the module removed from the base housing;

FIG. 13 is an exploded perspective view of the arrangement of FIG. 12with control and drive circuitry removed;

FIG. 14 is a perspective view of a thermal base and power electronicssubstrate and device subassembly of the type employed in the arrangementof FIG. 13;

FIGS. 15A–15R are diagrammatical detail views of exemplary arrangementsfor mounting and removal of heat from the power electronics substrateand thermal base;

FIG. 16 is an exploded perspective view of one arrangement for providinga switch frame on a thermal base where the switch frame is removablefrom the base;

FIG. 17 is a perspective view of a substrate for use with a thermal baseand illustrating an exemplary layout of power electronics devicesubassemblies on the substrate;

FIG. 18 is an exploded perspective view of one of the exemplary devicesubassemblies shown in FIG. 17 and a preferred manner of forming thedevice subassembly on the substrate;

FIGS. 19A and 19B are perspective view of an exemplary terminal stripemployed with a thermal base for routing incoming and outgoing power topower electronic devices and their associated circuitry;

FIG. 20 is a diagrammatical representation of a preferred layout ofterminals and conductors in a terminal strip of the type illustrated inFIG. 19;

FIG. 21 is a circuit diagram illustrating the signal flow offeredthrough the layout of FIG. 20;

FIGS. 22A–22F are diagrammatical perspective views of an exemplary powerelectronics module illustrating various possible routing orientationsfor incoming power, outgoing power, and coolant;

FIG. 23 is a perspective view of an exemplary connector interface foruse in a power electronics module in accordance with aspects of thepresent technique;

FIG. 24 is a perspective view of an alternative connector interfacearrangement designed to achieve various orientations of the typeillustrated in FIG. 22;

FIG. 25 is a perspective view of an alternative configuration for powerelectronics module wherein a canister is provided for mounting andshielding of the module components;

FIG. 26 is a perspective view of the elements of FIG. 25 after mountingan assembly;

FIGS. 27A–27D are diagrammatical representations of alternative terminaland terminal assembly connection arrangements for use in a module inaccordance with the present technique;

FIGS. 28A–28D are diagrammatical representations of alternative terminaland terminal assembly cooling arrangements for use in a module inaccordance with the present technique;

FIGS. 29A and 29B are diagrammatical representations of alternativeterminal and plug configurations for EMI shielding and grounding for amodule in accordance with the present technique;

FIGS. 30A–30C are diagrammatical representations of alternative powerelectronics substrate mounting arrangements for interfacing with heatremoval structures in the module;

FIG. 31A is a diagrammatical prospective view of an alternative powerand control low inductance shield and ground arrangement for use in themodule, while FIG. 31B is an exploded perspective view of an exemplaryimplementation of such an arrangement;

FIG. 32A is a diagrammatical elevational view of an alternative plug-inmodule arrangement based upon the modules such as those illustrated inthe previous Figures, while FIG. 32B is a perspective view of anexemplary implementation of the plug-in module arrangement;

FIG. 33 is a further alternative plug-in arrangement incorporating suchmodules;

FIG. 34 is a diagrammatical representation of a module of the typeillustrated in the previous Figures incorporating flow control circuitryfor regulating the flow of coolant into and from the module;

FIGS. 35A–35C are diagrammatical views of circuits and physical layoutsof components for a converter arrangement employing aspects of thepresent technique;

FIGS. 36A–36C are diagrammatical views of circuits and physical layoutsof components for a matrix switch topology implementation of aspects ofthe present technique;

FIG. 37 is a further diagrammatical view of a circuit in accordance withthe passing technique adapted for supply of power for a mid-frequencywelding application; and

FIGS. 38A and 38B are exemplary configurations of modules adapted forcooling of circuitry through indirect conduction to the thermal support.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Before detailing specific embodiments of the inventive technique aspresently contemplated, certain definitional notes are in order.Firstly, reference is made in the present disclosure to power devicesand subassemblies incorporating such devices. Such devices may include arange of components, such as power electronic switches (e.g. IGBTs,FETs) of various power ratings. The devices may also include gate drivercircuitry for such components, sensing and monitoring circuitry,protection circuitry, filtering circuitry, and so forth. The devices maybe provided in the subassemblies in various groupings, both integrallyand separate from supporting substrates and/or thermal expansioncoefficient members and heat transfer elements. Reference is also madeherein to energy storage and conditioning circuitry. Such circuitry mayvary in composition depending upon the particular configuration of theassociated power electronic devices and circuits. For example, ininverter drive applications as discussed below, the energy storage andconditioning circuitry may include one or more capacitors,capacitor/inductor circuits or networks. Filtering circuitry may also beincluded for signal conditioning. In other applications, such as mediumfrequency welding, the energy storage and conditioning circuitry mayinclude one or more transformers. Finally, while reference is madeherein to a thermal support used in conjunction with power devices andother circuitry, various configurations and functions may be attributedto the support. For example, as described below, the support may provideboth mechanical and electrical support for the various components, aswell as offer integrated and highly efficient cooling of some or all ofthe components. Moreover, the support may provide electrical andshielding functions, such as for EMI and RFI shielding both of externalfields that may affect the components as well as fields that may begenerated by the components during operation. Thermal regulatingcomponents and circuits may also be incorporated into or associated withthe support.

Turning now to the drawings, and referring first to FIG. 1, an exemplarypower electronics module 10 is illustrated. Module 10 includes a thermalsupport 12 on which power electronic circuit 14 is disposed. Asdescribed in greater detail below, thermal support 12 may include arange of thermal management features, such as porting for routing ofcoolant for extracting heat from circuit 14. Similarly, circuit 14 mayinclude a wide range of functional circuitry, such as invertercircuitry, converter circuitry, and so forth which is mounted on support12 for mechanical and electrical support, improved EMI/RFI shielding andhigh frequency grounding, as well as for extraction of heat generatedduring its operation. In the embodiment of FIG. 1, module 10 furtherincludes control and driver circuitry, designated generally by referencenumeral 16. Incoming power, as indicated by arrow 18 is applied tocircuitry 14 and outgoing power 20 is routed from the circuitry toexternal devices (not shown). Similarly, in the diagrammaticalrepresentation of FIG. 1, coolant 22 is applied to the thermal support12 to extract heat from the power electronic circuit 14 and from thethermal support, as well as from the control and driver circuitry 16.Outgoing coolant 24 is routed from the thermal support to carry heataway to a cooling system (not shown). In the embodiment of FIG. 1, boththe power electronic circuit 14 and the control and driver circuitry 16are mounted on a side 26 of the thermal support 12. Both incoming andoutgoing power are routed to the circuitry at an edge 28 of the thermalsupport. Finally, interconnections 32 are provided between the controland driver circuitry 16 and the power electronic circuit 14 for controlof operation of the circuitry as described more fully below.

FIG. 2 illustrates an exemplary alternative configuration of a powermodule 10 in which components are mounted on both sides of the thermalsupport. In the embodiment of FIG. 2, power electronic circuit 14 isagain mounted to side 26 of the thermal support 12. In the embodiment ofFIG. 2, however, driver circuitry 34 for controlling functioning of thepower electronic circuit is mounted to the same side 26 of the thermalsupport, while control circuitry 36 is separated from the drivercircuitry. Energy storage and conditioning circuitry, as indicatedgenerally at reference numeral 38, is also mounted on the thermal base.As before, interconnections 32 between driver circuitry 34 and powerelectronic circuit 14 are provided, as are similar connections 40between the control circuitry and the driver circuitry, andinterconnections 42 between the power electronic circuit 14 and theenergy storage and conditioning circuitry 38. As will be noted, in theembodiment of FIG. 2, the geometry, layout and space utilization of thethermal support are adapted such that the control circuitry 36 and theenergy storage and conditioning circuitry 38 are mounted on a lower side44 of the thermal support 12. All such components may therefore bemechanically and electrically supported on the thermal support, whilereceiving cooling via coolant flow as indicated by arrows 22 and 24.

FIG. 3 illustrates a further exemplary configuration of a module 10wherein power electronic circuits are mounted on both sides of thethermal support. Thus, as shown in FIG. 3, a thermal support 12 servesfor mechanical and electrical mounting of both power electronic circuit14, and control and a driver circuitry 16 with the necessaryinterconnections 32 being provided between these circuits. A secondpower electronic circuit 46, and second control and driver circuitry 48are provided on the opposite side of the thermal support 12 thus makingthe use of the cooling fluid nearly significantly more effective as itwould be with only one side of the heat exchanger used for activecooling. Thus, heat may be extracted from both power electronic circuitsbus work, input output terminals, energy storage elements and supportelectronics by virtue of coolant flow through or around the thermalsupport.

FIG. 4 illustrates a further exemplary configuration of a module 10. Inthe exemplary configuration of FIG. 4, power electronic circuit 14 isagain mounted to a side of the thermal support 16 along with control anddriver circuitry 16. Energy storage and conditioning circuitry 38 ismounted on an opposite side of the thermal support. In this alternativeconfiguration, a second thermal support 50 is secured to the firstthermal support 12, and itself supports additional energy storage andconditioning circuitry 38. As will be appreciated by those skilled inthe art, the particular circuitry supported on the one or moreadditional thermal supports may vary depending upon the system needs.Accordingly, capacitor circuitry, power electronic circuitry, drivercircuitry, control circuitry, energy storage components, inductors,filters, braking resistors, and so forth, or any other ancillarycircuitry may be provided on the additional thermal support. Moreover,in the embodiment of FIG. 4, coolant is routed separately to the secondthermal support 50. A modular system of stacking interconnect, thermalconnection, and support features may be provided such that thermal base,power terminal assemblies can interconnect in parallel and seriescombinations to form larger and differently rated power converters usingthe core thermal-electrical base described. Depending upon thermalmanagement needs and available plumbing, however, coolant could berouted to one of the thermal supports alone, or coolant could be routedinternally between the thermal supports. Similarly, interconnection 52made between the energy storage and conditioning circuitry 38 of FIG. 4could include a range of interconnections between functional circuitry,including power electronic circuits, and their associated drive andcontrol circuits.

The exemplary configurations of FIGS. 1–4 can be adapted to support awide range of functional power electronic circuits. FIGS. 5 and 6illustrate exemplary applications of the power electronics modules. Inthe illustration of FIG. 5, a vehicle drive 54 is provided, such as adrive for an automobile or other mobile application. The vehicle drive54, which may include the functional circuits of FIG. 5 as well as awide array of additional support, control, feedback and otherinterrelated components, will generally include a power supply 56 whichprovides the power needed for driving the vehicle. In a typicalapplication the power supply 56 may include one or more batteries,generators or alternators, fuel cells, utility source, alternators,voltage regulators, and so forth. Power supply 56 applies power,typically in the form of direct current via direct current conductors 58to the power electronics module 10. Control circuitry 60 providescontrol signals for regulating operation of the power electronicsmodule, such as for speed control, torque control, acceleration,braking, and so forth. Based upon such control signals, powerelectronics module 10 outputs alternating current waveforms along outputconductors, as indicated generally at reference numeral 20 in FIG. 5.The output power is then applied to a vehicle drive train as indicatedgenerally at reference numeral 62. As will appreciated by those skilledin the art, such drive trains will typically include one or morealternating current electric motors which are driven in rotation basedupon the frequency and power levels of the signals applied by the powerelectronics module 10. The vehicle drive train may also include powertransmission elements, shafts, gear trains, and the like, ultimatelydesigned to drive one or more output shafts 64 in rotation. Sensorcircuitry 66 is provided for sensing operating characteristics of boththe vehicle, the drive train, and the power electronics module. Thesensor circuitry 66 typically collects such signals and applies them tothe control circuitry, such as for regulation of speeds, torques, powerlevels, temperatures, flow rates of coolants, and the like.

FIG. 6 illustrates a further application of a power electronics module10 in an industrial or mobile setting. In an industrial setting, thepower electronics module 10 may be applied for application of power tovarious loads, such as electric motors, drives, valving, actuators, andso forth. In the system, designated generally by reference numeral 68,an enclosure 70 is provided that may be divided into bays 72. Withineach bay various components are mounted and interconnected forregulating operation of processes, such as manufacturing, materialhandling, chemical processes, and the like. The components, designatedgenerally by reference numeral 74, are mounted within the bays andreceive power via an alternating current bus 76. A control network 78applies control signals for regulating operation of the components 74and of the power electronics module 10. An enclosure, such as enclosure70 may be included in various industrial settings, such as in motorcontrol centers, assembly line or process controls, and so forth.However, such enclosures may also be provided in a vehicular setting,such as for driving one or more drive trains of an automobile, utilityvehicle, transport or other vehicle.

As mentioned above, various circuit configurations may be designed intothe power electronics module. The circuit configurations will varywidely depending upon the particular requirements of each individualapplication. However, certain exemplary circuit configurations arepresently envisaged, both of which include power electronic deviceswhich require robust and compact packaging along with thermalmanagement. Two such exemplary circuits are illustrated in FIGS. 7A and7B. In FIG. 7A, the circuitry includes a rectifier circuit 80 whichconverts alternating current power from a bus 76 to direct current powerfor output along a DC bus, corresponding to incoming power lines 18. Aninverter circuit 82 receives the direct current power and converts thedirect current power to alternating current waveforms at desiredfrequencies and amplitudes. The alternating current power may then beapplied to a load via the outgoing conductors 20. Filter and storagecircuitry 84 may be coupled across the direct current bus to smooth andcondition the power applied to the bus. A control circuit 86 regulatesoperation of the rectifier and inverter circuits. In the example of FIG.7B, a direct and/or matrix converter 90 includes a set of AC switchingpower devices per phase of power controlled. Inverter 90 receivesincoming alternating current power and supplies an outgoing waveform topower switches 88. The set of AC switches effectively convert fixedfrequency incoming power 18 to controlled frequency outgoing power 20for application to a load. The arrangement of FIG. 7B is illustrated ingreater detail in FIG. 36C. It should be borne in mind, however, thatthe particular circuitry of FIGS. 7A and 7B are exemplary only, and anyrange of power electronic circuits may be adapted for incorporation intoa module in accordance with the present techniques.

FIG. 8 illustrates an exemplary physical configuration for a powerelectronics module 10. In the embodiment of FIG. 8, a circuit assembly92 is positioned within a housing 94 and enclosed within the housing bya cover 96 fitted to the housing. Circuit assembly 92 includes thecomponents described above, and in the particular embodiment illustratedcorresponds generally to the configuration of FIG. 2. As illustrated,thus, the circuit assembly 92 includes a thermal support 12 on whichpower electronic circuit 14 is disposed. Control and driver circuitryare also disposed on the thermal support for regulating operation of thepower electronic circuit with cooling of such circuitry. In theembodiment of FIG. 8, the module is particularly configured foroperating as an inverter drive for a vehicle application. Incomingdirect current power is received via conductors 18, and converted tothree-phase waveforms output via conductors 20.

In the embodiment of FIG. 8, housing 94 presents a control interface 98which is designed to permit control signals to be received within andtransmitted from the housing. As described in greater detail below, thecontrol interface may be provided on a bottom side of the housing asillustrated in FIG. 8, or at other positions on the housing. A powerinterface, designated generally by reference numeral 100 in FIG. 8, isprovided for transmitting power to and from the circuit assembly 92. Asdescribed below, various configurations can be provided and arepresently envisaged for interfacing the module 10 with externalcircuitry. In the embodiment of FIG. 8, for example, the power interface100 permits five conductors two direct current conductors and threealternating conductors, to be directly interfaced from the circuitassembly, such as in a plug-in arrangement. In addition to the controland power interfaces, a coolant interface 102 is provided for receivingand circulating coolant as described more fully below. In presentembodiments, the coolant interface may include tubes or specializedfittings adapted to receive conduits for channeling fluid to and fromthe module. It should be noted, however, that where appropriate,liquids, gases, compressed gases, and any other suitable cooling mediamay be employed in the present technique. Thus, while in vehicleapplications the combination of water and conventional vehicle coolantmay be used, other specialized or readily available cooling media may beemployed.

In the embodiment of FIG. 8, housing 94 forms a metallic shell, such asof aluminum, which is cast to provide shielding of EMI, both generatedby the module circuitry and which may be present in the environment ofthe module. Cover 96 is made of a similar material to provide shieldingon all sides of the module. As described below, connector interfaces mayalso provide additional shielding, and are particularly useful inapplications where high frequency waveforms are generated by the powerelectronic components, such as inverter drives. Where appropriate, othertypes of housings and supports may be employed. For example, wheresufficient EMI shielding is provided, or where EMI transmissions aresufficiently reduced by proximity of the power electronic components tothe thermal support, plastic housings, doped plastic housings, and thelike may be employed.

In the illustrated embodiment, housing 94 includes a cavity 104 in whichcircuit assembly 92 is disposed. Conductors 106 transmit DC power to thecircuit assembly 92, while conductors 108 transmit the AC waveforms fromthe circuit assembly 92 for application to a load. An interface plate110 is provided through which conductors 106 and 108 extend. Wheredesired, sensors may be incorporated into the assembly, such as currentsensors 112 which are aligned about two of the outgoing power conductors108 to provide feedback regarding currents output by the module. As willbe appreciated by those skilled in the art, other types and numbers ofsensors may be employed, and may be incorporated both within thehousing, within a connector assembly, or within the circuit assemblyitself.

As described more fully below, thermal support 12 may incorporate avariety of features designed to improve support, both mechanical andelectrical, for the various components mounted thereon. Certain of thesefeatures may be incorporated directly into the thermal support, or maybe added, as is the case of the embodiment of FIG. 8. As shown in FIG.8, a frame 114, made of a non-metallic material in this embodiment, isfitted to the thermal support 12, and components mounted to the thermalsupport are at least partially surrounded by the frame. The frame servesboth as an interface for conductors 106 and 108, and for surroundingcircuitry supported on thermal support 12 to receive an insulating orpotting medium. In the embodiment of FIG. 8 terminals 116 are formed onframe 114, and may be embedded within the frame during molding of theframe from an insulative material. A preferred configuration for theterminals is described more fully below. Separators 118 partiallysurround terminals 116 for isolating the conductors coupled to theterminals from one another.

An alternative configuration for the housing 94 and cover 96 of themodule is illustrated in FIGS. 9 and 10. As shown in FIG. 9, the housingmay provide for interfaces for power conductors at different locations,such as along topside as illustrated in FIG. 9 for incoming power, andalong an edge for outgoing power. Accordingly, an incoming powerinterface 120 may be specifically adapted to provide connections toconductors 106, such as from a DC power source. An outgoing powerinterface 122 may provide similar connections for conductors 108 used totransmit controlled AC waveforms to a load. As will appreciated, theinterfaces may be provided either in the housing itself or in the cover,or both. The coolant interface 102 may be similarly provided at variouslocations about the housing and cover, such as along an edge as shown inFIG. 9.

FIG. 10 is a rear prospective or the arrangement of FIG. 9. As shown inFIG. 10, the control interface 98 may be available from variouslocations on the housing and cover. In the embodiment of FIG. 10 amulti-pin connector 124 is provided for receiving a control cable. Pindesignations for the connection may follow any suitable protocol, and ina present embodiment may include pins designated for transmission to anRS232 or other serial or parallel data transmission port. Once closed,the housing and cover may define a water-tight, EMI-shielded packagewithin which the circuit assembly is positioned. Moreover, the packagingmay include any suitable handles, tool geometries, and the like forplugging the module into an application, or for otherwise supporting themodule in an application. For example, where a handle (not shown) isprovided on the package, the handle may be grasped by a user to simplyplug the module into a mating interface, such as within a vehicle orenclosure.

FIG. 11 illustrates certain internal configurations of the embodiment ofFIGS. 9 and 10 with cover 96 removed. As shown in FIG. 11, the module 10comprises the housing 94 in which the circuit assembly 92 is disposed.Conductors 108, separated by an interface plate 110 from the surroundingenvironment, are available for connection within power interface 122. Asimilar power interface may be provided, as illustrated in FIG. 9, forother power conductors. The control interface 98 is positioned on anopposite side of the housing in the embodiment of FIG. 11, and supportsmulti-pin connection 124.

In the arrangement of FIG. 11, an integral flange 126 is formed on thethermal support 12 and extends generally upwardly from the plane of thethermal support, partially replacing the removable frame illustrated inFIG. 8. The integral flange serves to support and interface the circuitassembly 92 within the housing (such as by mating with the cover wheredesired), and surrounds certain of the circuitry, such as to form acavity 128 within which the circuitry is mounted and within which aninsulating or potting medium may be disposed. Power electronic devicesubassemblies 130 are provided within the cavity, and form the powerelectronic circuits 14 as described more fully below. In the illustratedembodiment, six such device subassemblies or switching circuits areprovided for defining a three-phase inverter circuit. As will beappreciated by those skilled in the art, in practice, two or more suchswitching circuits may be grouped on each device subassembly, or entireset of circuits may be provided in a single device subassembly.Connection pads 132 are provided adjacent to device subassemblies 130for interfacing the device subassemblies with incoming and outgoingpower conductors. In the illustrated embodiment, a terminal strip 134,described in greater detail below, is provided at an edge of the thermalsupport 12, and mates with the integral flange 126 to define the cavitywithin which the circuitry is disposed and within which a potting mediummay be placed. The terminal strip may include molded-end features,including the connection pads 132, as well as terminals and conductorsas described below.

Within the housing, various other features may facilitateinterconnections between the various circuits and components. Forexample, in the illustrated embodiment sensor cabling 136 is providedfor receiving signals from current sensors 112. Such signals may berouted, via the cabling 136 around the housing to drive circuitry 34 orcontrol circuitry 36, so as to monitor operating conditions of the powerelectronic circuitry. Other types of sensors and placements of suchsensors, along with signal transmission cabling may, of course, beincorporated in the arrangement.

FIG. 12 illustrates the circuit assembly 92 of FIG. 11 removed fromhousing 94. Again, in the illustrated embodiment the thermal support 12is provided with an integral flange 26 which partially surrounds thepower electronic circuit 14. In the illustrated embodiment, the drivercircuitry 34 for the device subassemblies 130 is also provided withinthe cavity defined by flange 126. The driver circuitry 34 and thecontrol circuitry 36 may be provided on a single printed circuit boardor on two or more boards, and may define a single-sided board componentarrangement or double sided arrangement. Where a double-sided board isprovided, spacers, standoffs, or similar arrangements may be providedfor insuring that an insulating or potting material may be providedbetween the board and the thermal support.

Returning to FIG. 11, to provide the desired sealing, a peripheral edge138 may be provided on the housing and cover, with a groove 140, orother interface feature, provided for receiving a seal, a sealingcompound or the like. As shown in both FIGS. 11 and 12, while one ormore of the circuits may be provided on a top or bottom side of thethermal support as described above, in the present embodiment, a rearboard support 142 is provided as an integral feature of the thermalsupport 12. Thus, the control circuitry 36 may be supported on the rearboard support 142 and interfaced directly with the driver circuitry viainterconnections 40. These features of the present arrangement are bestillustrated in FIG. 13, where the drive circuitry 34 and controlcircuitry 36 have been exploded from the thermal support to illustratethe manner in which they may be disposed and interconnected along withcabling 136 from sensors 112. As also shown in FIG. 13, housings 144 maybe incorporated in the design, such as to support sensors 112.

A variety of interface configurations may be envisaged for mounting thevarious components on the thermal support 12. In the embodimentillustrated in FIG. 13, for example, an energy storage and conditioningcircuitry package 38 is enclosed in a housing 146 which is mounteddirectly to a lower side of the thermal support 12. Capacitors withinthe housing 146 are interconnected with the power electronic circuitryas described more fully below. As also shown in FIG. 13, an interfaceplate 148 is secured to the thermal support 12 and the power electronicdevice subassemblies 130 are disposed directly on the interface plate148. Thus, in accordance with aspects of the present technique, thedevice subassemblies may be formed directly on and processed on theinterface plate 148 which is later secured to the thermal support 12.Special processing, therefore, of the components making up devicesubassemblies 130 is facilitated by separately processing the devicesubassemblies and interface plate 148, and later assembling theinterface plate with the thermal support. FIG. 13 also shows anexemplary connection sensor 113 coupled to cabling 136 for detectingwhether appropriate connections have been made to the module (e.g., toprevent operation until such connections are completed), as describedbelow.

As illustrated in FIG. 14, the interface plate 148 is assembled with thethermal support 12 in a present embodiment. Various securement featuresor pads may be provided on the thermal support 12, such as indicated atreference numeral 150 in FIG. 14. The pads provide locations at whichthe thermal support may be secured within a housing of the typedescribed above, or another mechanical structure. The thermal supportitself is preferably made of a conductive metal, such as aluminum. Thesupport may be formed in any suitable manner, such as by assembly,machining, or, as in a present embodiment, by casting followed bycertain machining operations. The support includes features whichfacilitate circulation of coolant for extracting heat from the powerelectronic circuit 14. In the embodiment of FIG. 14, these featuresinclude a trough or channel 152 formed within the thermal support. Thechannel extends between the coolant inlet 22 and the coolant outlet 24for the circulation of coolant. The channel preferably extends at leastalong an area of the interface plate 148 to remove sufficient heat fromthe circuitry during operation, and may route coolant through otherportions of the thermal support, such as those supporting othercircuitry and components. In the illustrated embodiment, channel 152extends beneath the interface plate 148, adjacent to a lower surface onwhich the energy storage and conditioning circuitry is mounted.

Features are formed within channel 152 for enhancing the heat transferfrom the power electronic circuit. In the embodiment of FIG. 14, adiversion plate 154 is secured within the channel for diverting coolantwithin the channel. As described in greater detail below, additionalheat transfer elements, such as fins or other cooling features may alsobe positioned within the channel, and may be integral with or separatefrom the interface plate 148. As also illustrated in FIG. 14, thermalsupport 12 may include sealing features to ensure isolation of thecoolant from the circuitry mounted thereon. A peripheral channel 156 isformed in a present embodiment to receive a seal (not shown) fittedbetween the thermal support 12 and the interface plate 148. The sealboth promotes isolation of the coolant from the circuitry, and allowsfor some degree of differential thermal expansion and contractionbetween the interface plate 148 and the support 12. Finally, in theillustrated embodiment, a baffle 158 is formed within channel 152 tofurther direct coolant through the channel for heat extraction. As willbe appreciated by those skilled in the art, various alternativeconfigurations, impingement surfaces, and flow of path-defining elementsmay be inserted into the thermal support to define desired thermalgradients and produce optimum patterns of turbulence and optimumtransitions between turbulent and laminar flow regimes within thesupport adjacent to the power electronic circuit 14.

FIGS. 15A–15G illustrate certain exemplary configurations of featuresenvisaged for removal of heat via the interface plate 148 and thethermal support 12. As shown first in FIG. 15A, the interface plate 148may include integral features, such as fins 160, small heat pipes,impingement targets, turbulators. In the present embodiment, plate 148is made of a material dissimilar to that of which the thermal supportitself is comprised. The material may be adapted to the particularelectronics and the methods for processing the electronic devicesubassembly. In a present embodiment, plate 148 is made of aluminumsilicon carbide (AlSiC). A seal 162 is positioned adjacent to theinterface plate 148 and would be received within a groove of the typeillustrated in FIG. 14. Along a lower surface 164 of plate 148, a seriesof fins 160 are formed, such as during a casting operation. The finscould also be added to the plate in an assembly process. The plate alsopresents an upper surface 166 on which the power electronic devicesubassemblies 130 are formed as described in greater detail below.

Where fins 160 extend from plate 148, various types of fins and patternsof arrangement may be provided. As illustrated in FIG. 15B, the fins maybe formed as pins 160 which extend from the lower surface of the plate.Again, any desired form of pin may be provided, such as pins having agenerally trapezoidal cross section. In the embodiment of FIG. 15B, astraight matrix pattern 168 is provided with the pins being alignedwithin parallel rows and columns. As illustrated in FIG. 15C, staggeredpatterns 170 may be provided in which rows or columns of pins are offsetwith respect to one another. Moreover, as illustrated in FIG. 15D, pins160 may extend from plate 148, while additional pins or other thermaltransfer features 170 may intermesh with the pins of the plate, andextend from other plates, or from the base of the channel 152 formedwithin the thermal support. The fins, pins, or other thermal conductionextended area enhancements may be staggered in pitch such that whenassembled one on top of the other or when inserted from opposite sidesof the thermal base the patterns inter-mesh to form optimum arrangementand minimum geometry that cannot be achieved effectively by a singlemanufactured piece.

FIG. 15E illustrates an alternative configuration in which the interfaceplate 148 does not include integral thermal transfer features, butwherein a heat dissipation element 174 is assembled between theinterface plate 148 and the base of channel 152. In a presentembodiment, element 174 may include a corrugated or bent-fin structurehaving a plurality of generally parallel sheet-like sections defining alarge surface area for heat removal; in addition, many other extendedsurface enhanced configurations can be accommodated by this mechanicalarrangement such as metal foams, metal matrix foams, metal polymermatrix foams, and so forth. As a further alternative configuration, asillustrated in FIG. 15F, thermal transfer features may be formed onadditional elements interfaced with the thermal support. In the exampleof FIG. 15F, power electronic device subassemblies 130 are mounted to apair of plates on either side of the thermal support. In this case, eachof the interface plates includes thermal features which extend intochannel 152 for heat removal. It should be noted that where 2-sidedarrangements are utilized, channel 152 may define an aperture extendingcompletely through the thermal support, or may form two separatechannels with flow paths interconnecting with one another.Alternatively, two completely separate channels may be formed within thesupport. Finally, as noted above, various alternative flow paths may beprovided within the thermal support, as illustrated generally in FIG.15G. Thus, owing to the form of the channel, any diversion plates andbaffles, and the like within the thermal support, a flow path 178 may bedefined which routes coolant in a desired path so as to establish thedesired temperature gradient within the thermal support.

FIGS. 15H–15R represent additional alternative flow and coolingconfigurations designed to extract heat from the power electronicdevices during operation. As illustrated in FIG. 15H, the thermalsupport 12 may include a diversion plate 154 provided with apertures 155for directing flow. Flow may thus be directed through the diversionplate between a coolant inlet 22 and a coolant outlet 24. As flow isdirected by the diversion plate and through the apertures, it ispermitted to flow adjacent to the interface plate 148, and through oraround a heat dissipation element 174 as shown in FIG. 15I. In thealternative arrangement of FIGS. 15J and 15K, a diversion plate 154 isagain provided with a series of apertures 155. Flow is directed througha coolant inlet 22, around and through the diversion plate, and exitsthrough a return channel 153. As shown in FIG. 15K, the arrangement maymake use of a baffle 158 for defining a passageway between channel 152and channel 153, and for partially partitioning these channels from oneanother. As shown in FIGS. 15L and 15M, in a further alternativearrangement, coolant inlet and outlets may be provided on the same sideof the thermal support 12. Apertures 155 in diversion plate 154 mayprovide for routing coolant upwardly into close contact with interfaceplate 154 for flow through or around a heat dissipation element disposedbetween the pair of channels 152. In FIGS. 15N and 150 a diversion plate154 is again positioned between the interface plate 148 and an internalbaffle 158 to cause flow to rise up above the diversion plate andthrough or around a heat dissipation element. Again, flow is thusdirected adjacent to the interface plate for heat removal. In thealternative of FIGS. 15P and 15Q, apertures 155 are provided in adiversion plate 154 and direct flow from a central channel 152 upwardlyand around heat dissipating fins extending from the interface plate 148as described above. Flow is then directed downwardly and into returnchannels 153 on either side of the central channel 152. Finally, asshown in 15R, a diversion plate may be provided in a constructionsimilar to that described above with reference to FIGS. 15A–15E. In thisembodiment, however, a baffle 158 is provided to define channels 152.Flow is then directed from a coolant inlet 22 upwardly, around thediversion plate, and through heat dissipating elements, such as pins 160and 172 extending from the interface plate 148 and from the diversionplate 154, respectively. Following flow through the circuitous pathdefined by the pins, flow is directed downwardly into the oppositechannel 152 and outwardly through the coolant outlet 24.

It should be noted that the various alternative configurations describedherein for routing coolant can be subject to wide variation andadaptation depending upon the heat dissipating requirements, theconfiguration of the thermal support, the location and disposition ofthe power electronic circuits, and so forth. The examples provided areintended to be exemplary only.

As described above, the interface plate 148 may be separately fabricatedfrom the body of the thermal support 12. Moreover, the thermal support12 may incorporate a substantial number of features useful forextracting heat, mechanically mounting the various circuitry andcomponents, establishing an electrical reference plane for thecircuitry, and shielding the surrounding circuitry, at least somewhat,from stray electromagnetic interference generated by operation of thepower electronic devices. The thermal support structure may be formedout of a number of materials and manners (e.g., polymers, polymer matrixcomposites, thermosetting materials and processes, utilizing a number ofnet shape, forming, discrete machining, fixture bonding, and similarProcesses). The number of integrated features that the thermal base mayprovide may be broken into cellular elements that can be included orexcluded by means of settings in the tooling of manufacture so that manypower electronic designs, topologies, and configurations can be built toorder from the core elements embodied in the tooling and design.Moreover, features may be formed on or added to the thermal support forreceiving the interface plate 148 and for defining a volume in which aninsulation or potting material may be deposited. In present embodiments,the thermal support may include a partial integral flange 126 (see,e.g., FIG. 14). In alternative arrangements, a frame 114 may be added tothe thermal support to accomplish certain of the mounting and insulationand potting functions, as illustrated in FIG. 16. In this embodimentalso, however, the thermal support 12 is fabricated separately from theinterface plate 148 to permit any special processing of the circuitrydisposed on the interface plate.

FIG. 17 illustrates an exemplary interface plate 148 with powerelectronic device subassemblies 130 disposed thereon. As noted above,the interface plate forms a substrate on which the power electronicdevice subassemblies are disposed, and may be made of any suitablematerial. In a present embodiment, however, the plate is made of AlSiC.The material of which the plate is fabricated is preferably at leastpartially thermally matched to the materials utilized for the powerelectronic device subassemblies disposed thereon. Thus, while differentcoefficients of thermal expansion will be anticipated between thematerials, these are preferably kept to a level sufficiently low toreduce stresses between the materials and to prevent or significantlylimit delamination of the materials from one another during their usefullife.

An exemplary electronic device subassembly is illustrated in FIG. 18. Asnoted above, the electronic device subassembly 130 is placed directly onthe interface plate 148 to promote good thermal transfer from theelectronics devices to the interface plate. In the embodiment of FIG.18, a bonding layer 180 is disposed on the plate 148 at a pad locationcorresponding to the location of the respective device subassembly 130.A substrate 182 is then placed on the bonding layer 180. The substrateincludes pad locations for mounting the power electronic circuits andfor interconnecting circuits with external circuitry. In the illustratedembodiment, the substrate 182 is a direct bond copper or direct bondaluminum substrate including pads for the electronic devices and padsfor wire bonding the interconnections between the devices and theinterfacing circuitry. A ceramic electrical insulating layer and a metallayer beneath the ceramic layer may be provided, but are not visible inFIG. 18. Thus, regions of direct bond material 148 are formed directlyon the substrate prior to assembly. At locations where the electronicdevices are to be placed, additional bonding layers 186 are provided.Bonding layers 186 may be similar to bonding layer 180 interposedbetween the substrate 182 and the interface plate 148. Where desired,sensors may be incorporated into the device subassembly, such as atemperature sensor 188 in the embodiment illustrated in FIG. 18. Thepower electronic devices are then placed on the bonding layers 186. Inthe illustrated example, each device subassembly 130 forms a portion ofan inverter circuit, and thus includes a solid state switch assembly 190(such as an IGBT assembly) and a fly-back diode assembly 192. Again,interconnections between the switch assembly 190 and the diode assembly192 are made subsequently by wire bonding.

The device subassembly design illustrated in FIG. 18 provides severalsignificant advantages. For example, a grease layer which mightotherwise be employed in such arrangements is eliminated by directbonding of the device subassembly to the interface plate 148. The use ofdirect bond copper or direct bond aluminum for substrate 182 provideshigh voltage insulation, good thermal characteristics, and goodexpansion control during operation of the device. Again, the selectionof the particular materials employed in the device subassemblypreferably provide for reduced differential thermal expansion andcontraction, at least for adjacent components of the device subassembly.Where desired, the material selections may provide for a gradient inthermal expansion and contraction coefficients to further reducestresses.

FIGS. 19A and 19B illustrate a present embodiment for a terminal stripused to channel power to and from the power electronic devices describedabove. The terminal strip is particularly well-suited for use with athermal support of the type illustrated in FIG. 11–13. The features ofthe terminal strip may, however, be incorporated into other types ofstructures within the device, such as the frame 114 illustrated in FIG.16. The terminal strip 134 includes features designed to serve asterminal or contact points for the conductors described above. The stripalso provides conductive elements or straps which communicate betweenthe power electronics circuitry and energy storage and conditioningcircuitry, thereby eliminating the need for a DC bus as in conventionaldevices. Thus, as illustrated in FIG. 19A, terminals 116 are providedfor the outgoing power conductors (not shown in FIG. 19A). Terminals 116are separated from one another and from conductors for the incoming DCpower by insulative separator 118. On a back side of the terminal strip134 a series of connection pads 132 are provided and are integral withthe terminal conductors as described below.

As shown in FIG. 19B, on a connection side of the terminal strip,terminals include elements designed to interface with conductors for theincoming DC power in the embodiment shown. It should be borne in mind,however, that where other power types and ratings are provided, such asfor incoming and outgoing AC power as in converter circuits, theconfiguration of the terminal strip can be adapted accordingly.

The terminal strip illustrated in FIGS. 19A and 19B is particularlywell-suited for fabrication via molding operations, being itself made ofan insulative material. The various conductors and conductive elementsof the terminal strip may be molded in place within the insulativematerial so as to be easily retained within the material for laterinstallation and connection. As shown, in FIG. 19B, power terminalconductors 194 are embedded within the insulative material of theterminal strip for connection to leads or conductors interfacing theterminal strip with outgoing power lines. Additional terminals 196 areprovided for similar leads for coupling the terminal strip to incomingpower conductors. In the embodiment illustrated in FIG. 19B, theterminals 196 are formed as conductive straps which permit connection ofthe incoming power, typically direct current power in an inverterapplication, with elements on both sides of the thermal support asdescribed below. In particular, because in applications requiring energystorage and conditioning circuitry conductive paths may be requiredbetween the power electronic devices and a capacitor bank, thearrangement of FIG. 19B permits such connections to be easily madewithout the need for a DC bus. Accordingly, it has been found that thearrangement reduces the incidence of parasitic inductance within theassembly. In the embodiment of FIG. 19B, similar conductive straps 198are provided at ends of the terminal strip to further facilitateconnection to the power electronic devices as described more fullybelow. The molded (or net shaped) interconnects can be made of variouscombinations of thermally conductive but electrically insulatingmaterials or elements. These may include but are not limited to:thermally conductive polymers, polymer combinations with direct bondcopper, direct bond aluminum, ceramic metal sprayed systems, sheetelectrical insulators, fluid coolant ports and passages, and so forth.By using thermally conductive polymers (which may, however beelectrically insulating) for the support structure of the conductors interminal strip 134, a direct thermal path between the conductors 116 and198 and the thermal support 12 allows for cooling of those conductorsand interconnections with them. This provides a major cooling path forthe conductors and reduces heat flow into any components connected tothem. This also allows for reduced heating of the energy storage andconditioning circuitry package attached to the terminal strip, as wellas any connector circuitry also attached to the terminal strip. Thereduced heating, in turn, promotes greater reliability of the circuitcomponents as well as a higher electrical rating. A further benefit ofthe arrangement is to reduce stress on external, interconnectingcomponents and circuitry.

As shown in FIG. 20, the arrangement of the terminal strip of FIGS. 19Aand 19B facilitate interconnection of the power electronic devicesubassemblies 130, the energy storage and conditioning circuitry 38, andthe terminals of the device. In particular, the arrangement of FIG. 20provides power electronic device subassemblies 130 arranged in a row ofsix device subassemblies. In a typical inverter application, two suchdevice subassemblies will be associated with each output phase so as toprovide positive and negative lobes of a simulated AC waveform. In thearrangement shown, first end pads, which may be referred to as DC endpads 200A and 200B, are provided adjacent to each end of the terminalstrip. End pads 200A and 200B correspond to the end pads 132 adjacent toends of the terminal strip illustrated in FIG. 19A. Additional pads 202Aand 202B are provided spaced from pads 200A and 200B at locationscorresponding to the incoming power terminals 196 (see, e.g., FIG. 19B).Finally, pads 204A, 204B and 204C are provided at locationscorresponding to the outgoing power terminals 194. Pads 200A and 202B,and pads 200B and 202A are interconnected as illustrated in FIG. 20 soas to electrically couple the pads adjacent to ends of the terminalstrip to the pads adjacent to terminals 196 as shown in FIG. 20. Thesesame interconnected pads are then electrically coupled to high and lowsides of the energy storage and conditioning circuitry 38 as illustrateddiagrammatically in FIG. 20. The device subassemblies 130 are thenelectrically coupled to pads 200A, 200B, 202A, 202B, 204A, 204B and 204Cas illustrated in FIG. 20 such as by wire bonding connections 206. Thiswire bonding, it will be noted, effectively couples each devicesubassembly both with a pad electrically coupled to the energy storageand conditioning circuitry 38, and to a pad associated with an outgoingpower terminal 194. Many alternative methods of bonding the devicesubassemblies to the power terminations may be envisioned in the presenttechnique; for example: tape bonding, metal braid resistance welding,brazing, mechanical attachment, laminated thin metal tapes, soldered orbrazed metal straps with intrinsic strain relief, flexible metal strapswith gas tight pressure connections, and so forth. Each pair of devicesubassemblies then, defines a portion of the inverter circuit for eachphase of outgoing power.

FIG. 21 illustrates diagrammatically the electrical circuit establishedthrough the terminal and interconnection arrangement of FIG. 20. Asshown in FIG. 21, control circuitry 36 is interconnected with drivercircuitry 34 in a typical inverter drive application, such as viainterconnections 40. The driver circuitry 34, which may be mounted onthe same side of the thermal support described above as the powerelectronics devices forming the inverter circuit itself, isinterconnected with the device subassemblies 130 via additional wirebonding 208. Each device subassembly 130, then, is electrically coupledto an output terminal 194 positioned at alternate locations along theterminal strip illustrated in FIGS. 19A and 19B. The devicesubassemblies 130 are also electrically coupled to the incoming powerterminals 196, and circuitry 38 is similarly coupled to the terminalsvia the straps 98 illustrated in FIG. 19B. Also in the exampleillustrated in FIG. 21, sensor circuitry 112 is associated with at leasttwo of the outgoing power lines.

As noted above, the packaging and configuration of the module 10 may bearranged so as to permit incoming power and outgoing power to be routedin a variety of manners depending upon the arrangement of interfacecircuitry and components. The packaging may also permit various routingarrangements for coolant. FIGS. 22A–22F illustrate exemplaryarrangements for such routing options. As shown in FIG. 22A, a firstconfiguration 210 corresponds generally to that illustrated in FIG. 8.That is, incoming power conductors 18 are provided along an edge 28 ofthe module, along with outgoing power conductors 20. Incoming coolantline 22 is provided along an adjacent edge offset from edge 28, alongwith outgoing coolant line 24. In an alternative configuration 212 shownin FIG. 22B, the incoming power conductors 18 and outgoing powerconductors 20 are again provided along edge 28. However, coolant issupplied and returned via a manifold 222 provided along a bottom side224 of the module. In an other alternative configuration 214 shown inFIG. 22C, incoming power conductors 18 enter through a top side 226 ofthe module. Outgoing power conductors 20 are still provided along edge28, and coolant lines 22 and 24 are provided along edge 30. In anotherconfiguration 228 of FIG. 22D, incoming power lines 18 enter throughedge 28, as do outgoing power lines 20. In this embodiment, however,coolant enters through an edge 30 of the module as indicated at line 22,and is extracted from the module along an opposite edge at line 24. Aswill be appreciated by those skilled in the art, such arrangements maybe useful for establishing desired temperature gradients through themodule as defined by coolant flow and the positioning of heat-generatingelements within the assembly. In a further alternative configuration 218shown in 22E, all lines, incoming power 18, outgoing power 20, andcoolant lines 22 and 24, are accessed along edge 28. Thus, arrangement218 of FIG. 22E may facilitate one-sided or plug-in mounting of themodule. As a further example of alternative interconnections, theconfiguration 220 of FIG. 22F provides incoming power lines 18 along atop side of the module. Outgoing power lines 20 are provided along anopposite bottom side. Coolant may be routed through another surface,such as edge 230 as indicated for lines 22 and 24 in FIG. 22F.

As noted above, various connector configurations can be provided in thepresent technique for routing power and coolant to and from the module.FIGS. 23 and 24 illustrate exemplary configurations for plug-inconnections to the module. As illustrated in FIG. 23 where multipleconnections are provided on one surface of the module, a ganged-typeconnector may be employed. A connection interface, designated in FIG. 23by reference numeral 232 may thus include a plurality of conductorsextending from the module 10. In FIG. 23 connectors 106 and 108 have agenerally circular or cylindrical shape. Other forms may, of course, beemployed, such as flat conductors, plate-like conductors, angledconductors, and so forth. The connector interface 232 in FIG. 23 issurrounded by a peripheral flange 234 which serves both to align amating connector 236 and to extend shielding of the conductors beyondthe housing of the module. Accordingly, flange 234 may, where desired,be a metallic extension of the housing. The mating connector 236preferably includes an insulation plate 238 which forms a rear wall ofthe connector and which at least partially surrounds interface sockets240. The housing 242 of the mating connector 236 supports the insulationplate and interface sockets, and interconnections between the socketsand leads 246 are made within the connector. A peripheral wall 244 mayextend around the sockets to provide protection for the sockets,alignment with flange 234 of interface 232, and extension of shieldingto the sockets and connections once made.

The connections are made to the module, then, by simply plugging themating connector 236 into the interface 232 as indicated by arrow 248.As will be appreciated by those skilled in the art, various lockingfeatures, securement features, straps, fasteners, or the like may beprovided to ensure that the connector is fully and securely installed.Moreover, a sensor or switch assembly (not shown) may be provided ineither the connector interface 232 or the mating connector 236 to sensewhether the connection is appropriately completed. Feedback signals fromsuch devices may be used by the controller to prevent or limitapplication of power to the module until appropriate interconnectionsare made.

In configurations employing more than one entry location for conductors,multiple connectors may be provided as indicated in FIG. 24. Thearrangement of FIG. 24 provides two incoming power conductors 106 alonga top surface of the module, with three outgoing power conductors 108along a bottom surface as in the arrangement of FIG. 22F. As shown inFIG. 24, a first connection with the incoming power conductors fromleads 246 is made at an incoming power connection interface 250. Theincoming power connector 254, in the illustrated embodiment, may includea peripheral flange 244 as in the previous example, with an insulationplate 238 protecting connections between the leads and interfacesockets. The connector 254 is then simply plugged into the incomingpower connector interface 250. Outgoing power connections are made in asimilar manner via an outgoing power connector interface 252. Thisinterface, similarly, is surrounded by a peripheral flange 234. Aconnector 256, similarly surrounded by a peripheral flange 244 andhaving an insulation plate 238, is connected into the outgoing powerconnector interface 252. Again, shielding may be provided at one or bothlocations by the cooperation of the peripheral flanges. Also, securementdevices may be provided at each location to ensure that the connectorsare appropriately made. As in the previous example, sensors or switchesmay be provided in both connectors to ensure that the appropriateconnections are made prior to application of power to the module.

As mentioned above, various alternative configurations may be envisagedfor the particular external packaging of the module, as well as for itsshielding from stray EMI. FIGS. 25 and 26 illustrate exemplaryalternative configurations based upon a drop-in design. As shown in FIG.25, an interface plate 258 may be provided, as an example, withinterconnections made directly to a rear surface of the interface plate.The configuration of the module 10 may generally follow the linesdescribed above including fabrication about a thermal support 12.Coolant conduits 260 may be provided for routing coolant to and from thethermal support. In such cases, the coolant conduits may be routeddirectly through the interface plate 258. A canister-type housing 262(see particularly FIG. 26, is provided which connects to interface plate258 to surround, support and shield the module. Interconnections withthe interface plate may then be made via a ganged-type connector 236 asillustrated in FIG. 26.

FIGS. 27A–27D represent exemplary techniques for joining the contactswith terminal strip 134 to circuits formed in the power electronicdevice subassembly 130. In the exemplary embodiment of FIG. 27A, stampedor similar contact members 266 are soldered or otherwise bonded to thedevice subassemblies 130 and extend to the terminal strip 148. Theconnective elements 166 may be soldered, welded, brazed, laser or E-beamwelded, conductively adhesively bonded, or electrically coupled in anyother way to the device subassemblies 130 and to the terminal strip 134.Strain reliefs may be formed within stamped, coined, cut, or moldedconductive elements of this type to provide an optimal section for thetransmission of current. In the alternative illustrated in FIG. 27B,metal laminates, plastic metal tapes, multiple such tapes, electricalbraids, ribbons, and the like, denoted generally by reference numeral268 similarly extend between the circuits formed on the devicesubassembly 130 and the terminal strip 134. Electrical contact may alsobe provided via power assembly gas-tight pressure contact structures.Where desired, the separate elements of such tapes, ribbons or braidsmay be joined through a portion or their entire length, such as byresistance welding. In the further alternative illustrated in FIG. 27C,separate contact members 270 and 272 are provided on the devicesubassembly 130 and the terminal strip 134, and are joined to oneanother during assembly of the module. Each of the contact members maybe formed by any appropriate method, such as by stamping or coining, andbonding or otherwise securing the contact members electrically andmechanically to the device subassembly and terminal strip. Finally, asillustrated in FIG. 27D, an extension 274 of a thermally conductivelayer of the device subassemblies themselves may be provided forconnection to the terminal strip 134. For example, in modules employingdirect bond copper or direct bond aluminum, a conductor may be extendedfrom an output terminal to the terminal strip. Stress relief may beprovided as in the aforementioned arrangements, as well as selectivepatterning of the conductive layer of the device subassembly, wheredesired.

FIGS. 28A–28D illustrate alternative terminal and terminal assemblycooling arrangements. As mentioned above, both incoming and outgoingcurrent may be passed through terminal strip 134. In use, heating withinthe terminal strip may occur and may be extracted through anyappropriate arrangement, such as the arrangements illustrated in FIGS.28A–28D. In a first exemplary arrangement shown in FIG. 28A, theterminal strip comprises one or more sections 276 and 278 which may bemade of a thermally conductive, electrically insulating material thatsurrounds and supports the various conductive elements described aboveof the terminal strip. Examples of such materials might includeceramic-filled thermoplastics or liquid crystal polymers.

In the arrangement illustrated in FIG. 28B, a manifold 280 is formed forreceiving a coolant, such as by interconnection with the coolantpassages formed within the thermal support 12 as described above. Themanifold serves to feed channels 282 which route coolant into and out ofthe terminal strip for cooling purposes. In the arrangement of FIG. 28C,a thermal extension 284 is provided which adds surface area to contactbetween the thermal support 12 and the terminal. The thermal extension184 is designed to interface with a corresponding and similarly formedrecess or groove 286 formed within the terminal strip 134. As will beappreciated by those skilled in the art, any suitable configuration orcross-sectional shape for the extension and recess may be provided.Similarly, as shown in FIG. 28D, an extension 288 may be formed in theterminal strip 134 and designed to interface with a corresponding grooveor recess 290 formed within a portion of the thermal support 12.

FIGS. 29A and 29B represent alternative configurations for terminalplugs and connections useful in the various connection configurationsdescribed above. As shown in FIG. 29A, housing 94 is designed tosurround conductor 108, while conductor 108 receives lead conductor 246when the connector is made up. Housing 242 is provided on the matingconnector 236 and at least partially surrounds the lead conductor 246.An electrically insulating body 292 is provided within the housing 94around the conductor 108. A wire shield and ground connection 294 isprovided within the housing 242, while an insulating member 295 isprovided between the connection 294 and the lead conductor 246. Theresulting assembly provides for both a good electrical connection of theconductor of the module and the mating connector, as well as theoffering EMI shielding and continuity of shielding between the connectorand the module. FIG. 29B represents a similar arrangement, but wherein aconductive receptacle shell 298 is formed to interface with the flange244 of the connector housing 242.

FIGS. 30A–30C illustrate alternative power device substrate mounting andheat exchanging configuration for use in a module of the type describedabove. In the embodiment of FIG. 30A, an interface 300 is provided asdescribed above for transmitting thermal energy from the powerelectronic device subassembly 130 through the interface plate 148. Asshown in FIG. 30B, various arrangements may be provided for installingtwo or more power electronic device subassemblies 130 on a commonthermal support 12. For example, two such arrangements are illustratedin FIG. 30B, including channels 152 for conveying cooling fluid throughthe support. In one exemplary configuration, pins 160 extend from aninterface plate 148 and are cooled by fluid flowing through one of thechannels 152. In another exemplary configuration shown in FIG. 30B, aheat dissipation element 174 is disposed in a channel for similarlyremoving heat. The plate 148 may be attached by any suitable method,such as soldering, brazing, welding, or via adhesive and gaskets toprovide adequate sealing. The heat exchanger base module defined by thesupport may be made of any conductive metal or polymer or can be made ofa variety of non-conductive materials such as thermoplastics, thermosetplastics, epoxy cast structures, and so forth. Also shown in FIG. 30B,an insert molded seal flange 302 may be provided for enhancing the sealbetween the interface plate and the thermal support 12. Such sealflanges may be made by any suitable process, such as injection,compression, casting, vacuum casting, adhesive attachment, and so forth.The flange may be bonded during molding or as a secondary step into thethermal base, such as at an edge, flange or lip so as to seal againstthe opening provided in the thermal support for this purpose. As shownin FIG. 30C, a specially adapted interface surface 304 may be providedfor receiving a device subassembly and interface plate assembly. Whereprovided, pins 160 or similar heat dissipation elements may extendthrough especially provided apertures 306 within the thermal support.Again, a sealing element 162 may be provided around the interface platefor sealing against the thermal support.

FIGS. 31A and 31B represent exemplary configurations for a lowinductance shield and ground arrangement for use in a module of the typedescribed above. In the arrangement shown in FIG. 31A, a thermal support12 includes a partial peripheral flange 126 as described above. Lowinductance paths for metal shielding may be formed as indicated atreference numerals 310, 312 and 314, with the paths 310 being providedon a cover 308 designed to be fitted to the thermal support. The groundpaths may be made of any suitable material, such as metallized polymersor may comprise metal or other conductive elements molded into polymericmaterials at specific locations as desired. The paths may be definedfrom intrinsic thinning of metal sections of castings and by shapingcontact areas for low inductance. Moreover, the paths may bespecifically shaped to provide high frequency power ground contacts, andthe paths may be brought into areas adjacent to the switch substrates.Laminated bus sections 311 may be provided that defines connectionsbetween the high frequency capable conduction paths. Bonding tabs 313may provide for connection between the bus and the device substrates.Through the use of such shielding approaches, the shell or housing forthe overall module may be made of metals, plastics (includingthermoplastics), or any other suitable material or combination ofmaterials.

FIG. 31B illustrates the power electronic device subassemblies 130disposed within an exemplary arrangement of the type shown in FIG. 31A.The cover 308, which acts as an EMI shield plate is placed over thesubassemblies, which constitutes combined gate driver circuitry andcontrol board circuitry in the illustrated embodiment. Mechanicalconnection and electrical paths are defined by fasteners used to securethe cover to the support 12.

FIGS. 32A and 32B, and FIG. 33 illustrate alternative exemplaryconfigurations for plug-in modules in arrangements accommodated bybackplane configurations. As shown in FIG. 32A, modules comprised ofthermal supports 12 and power electronic device subassemblies 130 arecoupled to terminal strips 134, with conductors 108 being electricallycoupled to parallel backplane conductors represented generally atreference numeral 322. The backplane conductors may route power to andfrom the modules once these are plugged into or otherwise coupled to thebackplane. The backplane represented generally by reference numeral 318in FIG. 32A, may also provide for connections to coolant streams. In theembodiment illustrated in FIG. 32A, for example, a coolant backplaneconnection adapter 326 serves to interface the inlet and outlet ports ofthe thermal supports with coolant supply lines 324 provided in thebackplane. The individual modules, then, may be plugged into thebackplane and connected for independent or joint operation in a largersystem. An exemplary physical implementation of a modular unit for suchbackplane configurations is shown in FIG. 32B, based generally upon thearrangement shown in FIG. 25. Handles may be provided on the package forfacilitating insertion and removal, while connections may be provided ona single side for completing all necessary interconnects to externalcircuitry. Moreover, sealed coolant conduits may be provided forinterconnecting to the coolant supply lines of the backplane. Theconnections may be extended at different lengths or designed inalternative manners, such as to ensure making or breaking of certainconnections before or after others during installation or removal. Thesemight include, but are not limited to, ultra-fast turnoff and ultra-fast“crowbar” function.

In the embodiment illustrated in FIG. 33, three such modules areprovided in a similar arrangement and are similarly coupled to thebackplane conductors 322 and coolant supply lines 324. However, as shownin FIG. 33, fluid connections may also be provided between the modulesas represented at reference numeral 330 to facilitate parallel or seriesflow of coolant among the various modules mounted on the backplane.

To enhance thermal control in modules of the type described above,various fluid flow controls may be incorporated into the structures asillustrated generally in FIG. 34. The flow control system, indicatedgenerally by reference numeral 332, may include various sensors 334which detect local temperatures at various locations around the powerelectronic device subassembly 130 and at other locations in the system.Input lines 336 feed signals representative of the temperatures to aflow control circuit 338. The flow control circuit 338 regulates theflow of coolant to and from the module via a flow control valve 340coupled to the flow control circuit via an output line 342. Thus,closed-loop temperature control may be provided in the module so as tooptimize coolant flow and to minimize variations in thermal cycling,thereby enhancing the life of the power electronic components within thedevice subassembly 130.

As noted above, a wide range of circuits may be accommodated that maybenefit from the various configurations described above. In particular,as mentioned above, various types of converter circuits may be supportedon the thermal support and connected, cooled, shielded and so forth asdescribed. FIGS. 35A–35C illustrate exemplary configurations forcircuitry which may define AC-AC converters, voltage source converters,synchronous rectifiers and similar topologies. In FIG. 35A, a devicesubassembly 130 comprises a series of solid state switches and diodescoupled to a DC source in half bridges. The individual subassemblies 130are mounted on a thermal support 12 as described above, and as shown inFIG. 35B. Electrically, the subassemblies 130 may be connected tocircuitry for producing controlled AC output signals, as illustrated inFIG. 35C.

Also as noted above, another type of circuitry which may be accommodatedin the arrangements described are AC-AC converters, matrix switchtopologies of the type illustrated in FIGS. 36A–36C. As shown, in suchtopologies each device subassembly includes a pair of switch and diodesets coupled to an AC power source. FIG. 36B illustrates a three phaseimplementation of such subassemblies mounted to a thermal support 12 asdescribed above. An input bus and an output bus are coupled to thesubassemblies for routing of input and output power signals. As shown inFIG. 36C, in the three phase implementation, phase inputs and outputsare electrically coupled to the subassemblies to produce the desiredpower output.

It should be noted that, while certain three-phase topologies arediscussed herein, the present technique may extend to single phase andother arrangements. Such arrangements may accommodate applications suchas mid-frequency welding applications. Such applications may incorporatea high frequency transformer rather than certain of the capacitorsdisposed on the thermal support. The circuitry supported on andthermally serviced by the support then becomes somewhat modular betweenapplication-specific designs.

FIG. 37 illustrates an exemplary circuit for one such application, inthis case a mid-frequency welding implementation. As will be appreciatedby those skilled in the art, in such applications, circuits 130 includepairs of solid state switches and diodes. The circuits are coupledthrough sources of power by the intermediary of transformers. Additionaltransformers are provided for output, such to a welding head. As in theprevious examples, both the circuits and the energy storage andtransforming circuitry may be supported and cooled by the thermalsupport and related techniques described above.

FIGS. 38A and 38B represent further alternative configurations in whichcooling may be provided at locations removed from the thermal supportitself. As shown in FIG. 38A thermal support 12 supports circuitrywithin a peripheral flange 126 as described above. Circuitry may bemounted to both sides of the thermal support 12 as previously described.Moreover, a cover 308 is provided, such as for providing the EMIshielding as described above. In the embodiment illustrated in FIG. 38A,a circuit board is mounted outside the primary cavity in which othercircuitry is mounted. In the illustrated embodiment, the circuit boardcomprises a control circuit board 36. Because the cooling requirementsof certain of the circuitry, such as the control circuit board 36, maybe less stringent than those of the other circuitry, such components maybe mounted remote from the thermal support 12. However, additionalcooling for such circuitry can nevertheless be provided, such as theheat pipes of the type illustrated in FIG. 38A and designated generallyby the reference numeral 344. As will be appreciated by those skilled inthe art, such heat pipes will typically comprise thermally conductivematerials which are extended into contact with the inlet and/or outletof the coolant stream. Conduction of heat along the heat pipe 344 thenpermits removal of heat from the circuitry mounted on board 36. FIG. 38Billustrates the same arrangement following assembly. An appropriatejumper cable 346 may be provided for channeling signals and power to andfrom the circuit board 36.

While the invention may be susceptible to various modifications andalternative forms, specific embodiments have been shown in the drawingsand have been described in detail herein by way of example only.However, it should be understood that the invention is not intended tobe limited to the particular forms disclosed. Rather, the invention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the followingappended claims.

1. A power converter system comprising: a backplane configured toreceive and circulate a coolant stream for extraction of heat; a firstpower converter module secured to and cooled by the backplane, the firstpower converter module having a first plurality of power switchingdevices secured to a first substrate, wherein the first power convertermodule is configured to be plugged into the backplane, to receive inputpower and to convert the input power to first output power havingdesired characteristics; and a second power converter module secured toand cooled by the backplane, the second power converter module having asecond plurality of power switching devices secured to a secondsubstrate, wherein the second power converter module is configured to beplugged into the backplane, to receive input power and to convert theinput power to second output power having desired characteristicsdifferent from those of the first output power.
 2. The system of claim1, wherein at least one of the first and second converter modules isconfigured to perform AC-to-AC conversion.
 3. The system of claim 1,wherein at least one of the first and second converter modules isconfigured to generate three-phase output power.
 4. The system of claim1, wherein at least one of the first and second converter modules isconfigured to receive DC input power.
 5. The system of claim 1, whereinthe backplane at least partially defines an electric reference plane foroperation of the first and second converter modules.
 6. The system ofclaim 1, wherein the backplane includes a channel for receiving acooling medium, and wherein each of the first and second substrates havea passage in fluid communication with the channel of the backplane forcooling the converter modules during operation.
 7. The system of claim6, comprising a flow control valve for regulation of fluid flow thoughthe backplane.
 8. The system of claim 7, comprising a thermal sensorcoupled to the flow control valve to permit closed loop control of fluidflow though the backplane.
 9. The system of claim 1, wherein the firstand second converter modules are configured to operate independently ofone another.
 10. A power converter system comprising: a backplane forrouting electrical power and thermal energy, the backplane includes achannel for circulation of a cooling medium; a first power convertersecured to the backplane, the first power converter including powerelectronics circuit configured to produce first output power havingdesired characteristics; and a second power converter secured to thebackplane, the second power converter including power electronicscircuitry configured to produce second output power independently of thefirst power converter; wherein at least one of the first and secondconverters includes a passage in fluid communication with the channelfor receiving the cooling medium.
 11. The system of claim 10, whereinthe backplane routes electrical power to and from the converters. 12.The system of claim 10, wherein at least one of the first and secondconverters is configured to perform AC-to-AC power conversion.
 13. Thesystem of claim 10, wherein at least one of the first and secondconverters is configured to generate three-phase output power.
 14. Thesystem of claim 10, wherein at least one of the first and secondconverters is configured to receive DC input power.